1. Field of the Invention
The present invention relates to devices for protecting occupants of a movable body such as a vehicle especially during a collision involving the vehicle. In particular, the present invention relates to a device for restraining an occupant in the manner of a seatbelt and having an air-belt inflated by gas provided by a gas generator.
2. Description of the Related Art
In an air-belt device, at least a portion, especially the portion touching an occupant""s body, of the webbing of a seatbelt device is implemented as an inflatable air-belt. When a collision or other emergency situation requiring protection of the occupant occurs, a gas generator is activated to inflate the air-belt. Japanese Unexamined Patent Publication No. 5-85301 and U.S Pat. No. 5,346,250, both of which are incorporated by reference herein, disclose an example of an air-belt device in which one end of an air-belt is connected to a tongue, and paths for gas are respectively disposed in the tongue and a buckle in which the tongue may be fitted, so that gas may be introduced into the air-belt via the paths. The other end of the air-belt is connected to a length of webbing identical to a conventional seatbelt device by sutures, and the length of webbing is wound onto a seatbelt retractor. A lap belt is formed of webbing identical to a conventional seatbelt and is connected to the tongue. When the air-belt is inflated by introduction of gas into the air-belt the length of the shoulder is shortened, creating a tension in the shoulder belt.
It is an object of the present invention to provide an air-belt device in which a portion of the tension generated in the shoulder belt is transferred to the lap belt while sufficient tension is applied to both the shoulder belt and the lap belt in order to protect and restrain the occupant.
An air-belt device according to the present invention comprises: an air-belt having a bag into which gas is introduced and a length of mesh webbing covering the bag; a tongue having a hole which the mesh webbing of the air-belt passes through; a buckle in which the tongue is mounted; a shoulder-side retractor for rolling up a shoulder-side end portion of the mesh webbing; a lap-side retractor for rolling up a lap-side end portion of the mesh webbing; a passage disposed in the buckle for carrying gas; and a gas-receiving means disposed in the tongue and connected to the bag positioned to mate with the passage when the tongue is mounted in the buckle, wherein a slit is formed in a side edge of the mesh webbing in the region of the hole in the tongue, and wherein the gas-receiving means is disposed in the slit. It is preferable that the slit in the webbing extend toward both the shoulder-side and the lap-side of the mesh webbing from the hole in the tongue.
In the air-belt device, the shoulder belt is drawn around the front portion of the upper half of an occupant body by mounting the tongue in the buckle. When a vehicle encounters an emergency such as a collision, gas is injected from the passage in the buckle into the bag via the gas-receiving means so as to inflate the bag and generate tension in the shoulder belt. The lap belt is drawn toward the shoulder belt to generate tension in the lap belt as well. A slit is formed in the length of mesh webbing of the air-belt. Because the gas-receiving means is inserted in the slit, when a tension is generated in the shoulder belt to draw the lap belt, the lap belt moves smoothly toward the shoulder belt through the hole in the tongue without obstruction. The gas-receiving means may be formed of a pipe-shaped nozzle to be connected to the tongue. It is preferable that the bag be connected to the rear end of the pipe-shaped nozzle.
According to the present invention, an air-belt device may further comprise a retaining member or stopper for securing the mesh webbing of the air-belt to the tongue. The retaining member may be located adjacent the hole in the tongue and may be released by when a predetermined force of more is exerted on the mesh webbing of the air-belt thereby allowing the webbing to pass freely through the hole in the tongue.
According to the present invention, the internal surface of the mesh webbing and the bag may be bonded together. Preferably the bonding releases when the bag is inflated.